Having defined the endo- and epicardial borders at all time points, and set up the segments, you can perform cardiac strain analysis. Strain analysis uses an image registration technique to assess the movement of tissue across time-points, and is applicable to any cardiac cine sequence, whether tagged or not.
Select the "Strain" tab in the Cardiac Segment toolkit:
Then press the button. This will start the registration process, and after a few minutes, you will see pop-up graphs showing the radial and circumferential strain in each segment through the cardiac cycle, and a dialog asking whether you want to save the results of the analysis to either a text or a PDF report: If you write a report, it will contain tables of radial and circumferential strain for each physical image slice. Any division into endo- and epicardium is ignored. In addition, there are bulls-eye plots and tables showing the minimum (maximum negative) circumferential strain and maximum radial strain, as shown in the examples below for a 6-slice image, where 4 of the slices has the endo- and epicardial borders defined, and the last 2 apical slices did not.
Strain analysis also outputs cine images showing the radial and circumferential strain through the cardiac cycle. The images will have the same name as the input image, but with the suffixes
_eRR
for the radial strain
image, and _eCC
for the circumferential strain. The examples
shown below were calculated from a regular (non-tagged) cine pulse sequence.
Radial strain image | Circumferential strain image |
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